Improvement in magneto-electric dial-telegraphs



3Sheets--/Sheetl. JOHNSON & WHITTEMORE.

Improvement in. Magneto Electric Dial-Telegraphs. No. 130,855. PatentedAug. 27.1872.

WITNESSES uwEN'l-Rsl` 3 Sheets--Sheet 2.

JOHNSON-8L WHITTEMORE. Improvement in Magneto Electric Dial-Telegraphs.

Patented Aug.27,1872.

. WITNESS E^S 3Sheets--Sheet3. JOHNSON & WHITTl-INIORE.4 Improvement inMagneto Electric Dial-Telegraphs;` N0. 130,855. v Patented Aug.27,1872.

WITNESSES UNITED STATES PATENT OFFICE.

JOHN B. JOHNSON AND HARRISON WHITTEMORE, `OF BOSTON, MASS.

IMPROVEMENT IN MAGNETvO-ELECTRIC DIAL-TELEGRAPHS..

Specification forming part of Letters Patent No. 130,85 5, dated August27, 1872.

Specification describing certain Improvements in YMagneto-Electric Dial-Telegraphs,

invented by J OHNB. JOHNSON, of Boston, in the countyof Suiolk andStateof Massachusetts, and HARRISON WHITTEMORE, of Boston in the county ofSuffolk and State aforesal Nature cmd Objects of om Invention.

Y strikes the bent -lever and raises its opposite' end so as to stop therevolution of the hook (hereafter referred to) and open the circuit atthe star When the key is released it returns to its former position. Ourinvention further relates to the .manner of attaching the case to thebase and connecting the wires between these parts; and consists of hooksand springs having bearings upon the same, by means of which the wiresare joined when the case is in position, thus allowing the case to beremoved without disturbing the wires. It also consists in a slopingcircle of keys, which are located ,radially around the dial, its objectbeing to facilitate the operation of selecting the letters andcharacters to be indicated. Our invention, as a whole, relates tomagneto-electric Vdial-telegraph instruments of the step-bystepdescription, wherein a circle of keys are employed to indicate theletters.

The advantages of this arrangement of the sloping circle of keys are thefacility and ease with which it is worked, the operator being enabled tosit at the machine and manipulate the keys and work the treadle at thesame time without obstructing his view ofthe dial.

Figure 1 is a perspective view of the case; also showing thealphabetical dial, stop-key, and index. Fig. 2 is a cross-sectional viewthrough the machine and case, as indicated by the dotted lines in Fig.1, w x. Fig. 3 is a top view of the machine, the case and dial bein gremoved, showing the hooks and springs, also lower portion of thestop-key. Fig. 4 is a detached view of a polarized electro-magnet andcall-bells. Fig. 5 is aview of a portion of a permanent horseshoe-magnet, with poles screwed directly into the ends of the outer bars.Fig. 6 is a section view through the springs and hooks, by which thecase is connected to the base and the circuit-wires are joined. Fig. 7is a section view of the polarized electro-magnet. Fig. Sis a rear-planview of the transmitter complete, the case being removed, theintermediate bars ofthe permanent horseshoe-magnet being broken away toshow the arbor carrying the armature. Fig. 9 is a transverse verticalcentral section through the same, as indicatedby dotted lines y y, Fig.8.

The frame I ot' the transmitter is secured to the base W in a positionsloping forward, as shown in Fig. 2. Within the lower portion ofthisframe we affix a permanent horseshoemagnet, P. We construct thismagnet with thick steel bars S S upon the outside, and screw thesoft-iron cores T T- of an electromagnet directly into the ends thereof.The intermediate bars R R may be of thinner steel, and more or less innumber. Into suitable bearings inthe frame I we affix an arbor, 3', withsuitable mechanism for revolving the same. wheel, 4, which gears into asmall pinion, 5, upon an arbor, 6, to which is also attached a soft-ironarmature, f. To the inner end of ar- .bor 3 is attached a small gear, 8,which gears into the toothed wheel J, which is constructed with acircular gear upon its under side for the purpose. This latter toothedgear-wheel J is attached to an upright arbor, both ends of which havebearings-the bottom in a suitable` step upon the frame I and the upperend in a bearing upon the under side of the dial-plate C, as shown inFigs. 2 and 9. Upon the arbor, immediately above the wheel J, is aprojecting arm, L, which carries a hook, K, which engages with thehooked teeth upon the periphery of wheel J. This hook K is held incontact with said teeth by a spring, N, attached to the arm L also, tothe opposite side of which is attached a weaker spring, M, and to theend is connected a loop, i, which surrounds the tail l1. of the hook-K.Supported upon standards just above the arm L isa circular ila-t ring,j, surrounding the upright arbor, having an outside diameter somewhatlarger than the To this arbor we aix a large gearcircle described by theouter end of the hook K. Through this ring j are drilled thirty holes,(equidistant,) and into these holes are itted the bodies of the keys Gso as to slide up and down freely. Surrounding these keys are spiralfriction-springs, which have a bearing upon Vthe top of the ringV j. Theupper portions or necks of the keys pass through corresponding holes inthe dial C, above which they terminate with small heads. These keys maybe pressed downward by the operator, so as to bring their lower endsinto the path of the collar i surrounding the. tail h of the hook K, andarrest the forward movement of the same by its contact with the lowerend of the depressed key, thereby removing the pressure of spring N, bywhich the hook K is held in contact with the teeth of the revolvin gwheel J. By the continued movement of the arm L the hookK is turned uponits bearin g until the arm L is stopped.- The spring M then throws thehook K away from the wheel J a sufficient distance to prevent itstripping or rattling upon the teeth of the same. The frictioncontact-bar 9, which eX- tends from the upright arbor referred t0, iskept in close contact with the hub of the carrying-arm L by afriction-spring, r, and, by the rotation of the hub,is held against thestop o; but when the motion of arm L ceases, spring n brings thecontact-bar against the stop o. and opens the circuit. The movement ofcontact-bar 9 is regulated at the outer end by a set-screw passingthrough stops o or o which project from the top of the hard-rubberinsulator 12. This insulator 12 is secured to the under side of the flatring j, (see Fig. S.) To the stop o is connected the end of the coilsurrounding the core of pole T, and to stop o is connected the wire fromthe coil surrounding thel pole T', which also connects with thecircuitwire t at the point u; the other circuit-wire t connecting withthe frame I of the transmitter. Attached to the under side of the ring jis a portion of the stop-key, which consists of a bent lever having abroad end, Hf, and the opposite end H anchor-shaped, the body betweenthe two being surrounded by a coiled friction-spring,g, which retainsthe bent lever in any desired position. Upon supports above the at ringj is attached the circular alphabetical dial C, which has arrangedaround it the twenty-six letters of the alphabet, abbreviations, and atthe top an asterisk. At the top right-hand of the circle of keys B is asimilar key7 G. This key G' is. attached to the cover A, and whendepressed its lower end strikes the broad end H ofthe bent lever andbrings its opposite end H in contact with the revolving hook K and opensthe circuit at the asterisk or star-key, and stops the hands of thereceivers (hereafter described) at that point, in which positionmessages may be received from a distant station. To thebase W ofthetransmitter is attached the case, having' a sloping cover, A,corresponding t6 the slope of the transmitter. Said case is providedwith a circular opening corresponding with the dial C, and surrounds thecircle of keys B which project above the same when in position. Thiscase is connected to the said base W by means of hooks E E', which lockunder plates upon the base. Upon the inner side of the case, near thebottom, are attached springs F F', whose free ends have a bearing uponthe plates of hooks E E on base W. To thc fixed ends of springs F F aresoldered the circuit-wires t t, and to the plates of hooks E E aresoldered the wires t. tl, thus connecting the circuit between the wiresupon the case and those upon the base W. To the sloping cover A of thecase is attached the receiver D, which has a peculiarly-constructedpolarized electro-magnet, U, with poles V V1. The bar of the magnet hasparallel arms of nearly equal length, to the longer one of which isattached the poles V V1, which extend across to near the shorter arm,where they terminate in iron caps. An arbor, having apivoted bearin g atits lower end, extends across from the longer arm to the shorter, whereit is also journ aled, and from this arbor extends a very short lighttongue, which rapidly vibra tes between the iron caps on poles V V1. Tothis tongue is connected a short arm with pin-pallets y, which propelthe wheel d by pressing against the unequal sides of the teeth of saidwheel. The teeth are V-shaped, and fifteen in number. This wheel isattached to an axis carrying the index-hand e. This axis is pivoted in astep at its lower end, and its upper end is journaled in the dial, overwhich the index-hand e revolves, and to which the hand is connected. Toprevent the momentum of the index-hand from turning the axis to which itis connected, a small frictionspring, Z, is attached, so as to have aslight bearing upon the saine.` To the rear of the case is attached thealarm or call bells Q Q. These call-bells are operated by a magnetexactly similar to the above-described polarized electro-magnet U3, withpoles V3 V3. To its short vibrating arm is attached the wire a,terminating in a loop, c, which surrounds the wire carrying the hammerb. This hammer b is suspended between and in close proximity to thebells, and receives its motion from the short vibrating arm.

Operation of our Invention.

this dial-plate are marked the twenty-six letters of the alphabet,several abbreviations, and at the top an asterisk; these are arrangedaround the circumference of the dial, making thirty divisions, or onefor each key. Also,

upon the top of the case is the corresponding small dial of thereceiver, which is exactly similar to the dial of the transmitter. Thisdial has a small indexhand or pointer turning with an axis through thecenter of said dial, and rotating in connection with the armature, whichmay be arrested at any letter by depressing one of the keys. Inside thecase is the fixed permanent horseshoe magnet, placed horizontally,carrying on its poles four softiron cylindrical cores with their coilsof wire, arranged at equal distances from each other in thecircumference of a circle. On the arbor passing through the center ofthis circle, in connection with the crank or driving mechanism, revolvesthe soft-iron armature. When the armature revolves, therefore, it`approaches one pole as it recedes from the one opposite, and thusinduces simultaneously currents in the four coils. When a key is presseddown in the transmitter it arrests the index hand or pointer of thereceiver at the letter corresponding with the one at the depressed key;this action of the depressed key opens the circuit at that letter. Thisis done by the arm attaehed to the arbor, which arm revolvesunderneaththe dial, coming in contact with the lower end of the depressed key.Motion is imparted to the arbor carrying the arm by the gear-wheels,which engage withapinion fixed to the arbor carrying 'the armature ofthe electro-magnet. The proportions are so adjusted that, for everycurrent induced in the coils,

' the arm shall advance the distance of one letter on the dial. If,therefore, the arm start freely from the star, when the armature is inmotion, and any key, as D for an example, be depressed, the rotation ofthe armature prod uces alternate electric waves while the arm 'alludedto is divided into thirty equal spaces,

exactly similar to the dial of the transmitter. On an axis in its centeris a pointer, to which motion is given by a small wheel, which hasfifteen unequal-sided teeth, which is carried by a short arm withpin-pallets. This arm is connected to the end of a very short vibratingtongue, which lies between the caps of two small electro-magnet coils;the latter exercise mutual attraction and repulsion on the tongue as thepositive and negative currents alternate, andthereby cause rapidvibrations ofthe same. The pin-pallets at the end .of the vibratingtongue work to and fro and strike against the teeth upon opposite sidesof the wheel, and thereby rotate the s ame. The electrical connectionsof all the coils of the transmitterand receiver are connected up in acommon circuit. When the armature of the transmitter is revolved and thecarrier-arm' is free to move around beneath the circle of keys and dial,currents alternately positive and negative traverse the line at everyletter which the arm passes beneath, moving the pointer-hand of-thereceiver correspondingly; but as soon as the carrier-arm is arrested -bycoming in contact with the depressed key the circuit is opened. Thehands of the receivers therefore stand still upon the same place uponthe dials until the key is released and the circuit closed by thecontact-bar. At the side of the transmitter a switch is arranged, which,when placed .upon a button, brings the alarm into circuit,

the receiver being thrown out 5 but when 'moved upon the oppositebutton, the alarm or tric dial-telegraph, of a sloping circle of keys,

B, arranged radially around acorresponding `sloping alphabetical dial O.

JOHN B. JOHNSON. HARRISON WHITTEMOBE. Witnesses:

SYLvENUs WALKER, GEORGE E. CARTER.

